In the bowl of a stand mixer, combine butter, granulated sugar, confectioners sugar and mix until just combined.

Drizzle in oil and pour in eggs and mix well.

In a bowl add the cream of tartar and salt to the flour and roughly sift.

Slowly add the flour to the butter mixer and allow the mixer to combine until the dough pulls away from the sides of the mixer bowl.

Using an ice cream/cookie scoop, scoop out golf-ball size portions on a parchment lined cookie sheet.

Roll out each cookie dough ball until it is smooth and round.

Using a kitchen glass that has been pressed into granulated sugar, press down on each cookie dough ball until the center of the cookie is pressed flatter than the edges. Repeat this on all cookies.

Bake for 8-12 minutes or until edges are just slightly starting to brown and center no longer appears wet.

SUGAR COOKIE FROSTING

In a clean bowl of a stand mixer fitted with a paddle attachment, combine butter, sour cream, and salt.

Once ingredients are fully incorporated, start adding the confectioners sugar, about a 1/2 cup at a time. (You may not need all 5 cups. Keep an eye on the frosting to determine when it has reached your desired consistency. If it gets too be too thick you can add some milk to loosen)